European Solar Telescope

The European Solar Telescope (EST) is a next generation large-aperture solar telescope. This 4-metre telescope will be optimised for studies of the magnetic coupling between the deep photosphere and upper chromosphere. This will require diagnostics of the thermal, dynamic and magnetic properties of the plasma over many scale heights, by using multiple wavelength imaging, spectroscopy and spectropolarimetry. To achieve these goals, the EST will specialize in high spatial and temporal resolution using various instruments simultaneously that can efficiently produce 2D spectral information. EST will be located in Canary Islands, one of the first-class locations for astronomical observations.

Why does this matter?

A consensus exists among solar astronomers worldwide that a significant increase in observing capability is needed to understand the fundamental processes that control plasma physics in the Sun's outer atmosphere, approaching the following key questions as a priority goal:

1. What can the Sun teach us about fundamental astrophysical processes? Observations of the Sun reveal intricate patterns of magnetic fields and the complex dynamics of a stellar atmosphere at the physically relevant spatial scales.

2. What drives solar variability on all scales? The Sun varies on a wide range of spatial and temporal scales, displaying important energetic phenomena over the whole range. We do not fully understand and cannot accurately predict basic aspects of solar variability.

3. What is the impact of solar activity on life on Earth? Solar magnetic activity variations induce terrestrial changes, which can affect millions of humans on short and long time scales. We need to predict disturbances of the space environment, which are induced by the Sun and to understand the links between the solar output and the Earth’s climate.

What is the European added value?

European solar physicists unanimously share the view that a large aperture new generation solar telescope is needed to further understanding of the fundamental processes of plasma physics in the Sun’s upper layers. The construction of a ground-based large aperture solar telescope equipped, with adaptive optics and integral field spectropolarimeters for observing astrophysical processes at their intrinsic scale, would allow interaction between magnetic fields and plasma in the solar atmosphere to be observed.

Building EST will guarantee European Solar Physics access to an essential tool for ground-based solar research that will bring in scientific benefits not only in quantity but also of the highest quality. EST covers the gap as such large-scale telescopes for solar physics do not exist in Europe. It is not only a key reinforcement in the strategy of developing the European research area in this field but also in the development and internationalisation for the Canary Islands' Astrophysics Observatories. Moreover EST will give European industry, which is very well equipped for this type of project, a unique opportunity to make returns on its expertise in the field.